1 /**
2 * collectd - src/contextswitch.c
3 * Copyright (C) 2009 Patrik Weiskircher
4 *
5 * This program is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License as published by the
7 * Free Software Foundation; only version 2 of the License is applicable.
8 *
9 * This program is distributed in the hope that it will be useful, but
10 * WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 * General Public License for more details.
13 *
14 * You should have received a copy of the GNU General Public License along
15 * with this program; if not, write to the Free Software Foundation, Inc.,
16 * 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
17 *
18 * Authors:
19 * Patrik Weiskircher <weiskircher at inqnet.at>
20 **/
22 #include "collectd.h"
23 #include "common.h"
24 #include "plugin.h"
26 #if !KERNEL_LINUX
27 # error "No applicable input method."
28 #endif
30 static void cs_submit (unsigned long context_switches)
31 {
32 value_t values[1];
33 value_list_t vl = VALUE_LIST_INIT;
35 values[0].derive = (derive_t) context_switches;
37 vl.values = values;
38 vl.values_len = 1;
39 sstrncpy (vl.host, hostname_g, sizeof (vl.host));
40 sstrncpy (vl.plugin, "contextswitch", sizeof (vl.plugin));
41 sstrncpy (vl.type, "contextswitch", sizeof (vl.type));
43 plugin_dispatch_values (&vl);
44 }
46 static int cs_read (void)
47 {
48 FILE *fh;
49 char buffer[64];
50 int numfields;
51 char *fields[3];
52 unsigned long result = 0;
53 int status = -2;
55 fh = fopen ("/proc/stat", "r");
56 if (fh == NULL) {
57 ERROR ("contextswitch plugin: unable to open /proc/stat: %s",
58 sstrerror (errno, buffer, sizeof (buffer)));
59 return (-1);
60 }
62 while (fgets(buffer, sizeof(buffer), fh) != NULL)
63 {
64 char *endptr;
66 numfields = strsplit(buffer, fields, STATIC_ARRAY_SIZE (fields));
67 if (numfields != 2) {
68 ERROR ("contextswitch plugin: ctxt in /proc/stat "
69 "contains more than 2 fields.");
70 continue;
71 }
73 if (strcmp("ctxt", fields[0]) != 0)
74 continue;
76 errno = 0;
77 endptr = NULL;
78 result = strtoul(fields[1], &endptr, 10);
79 if ((endptr == fields[1]) || (errno != 0)) {
80 ERROR ("contextswitch plugin: Cannot parse ctxt value: %s",
81 fields[1]);
82 status = -1;
83 break;
84 }
86 cs_submit(result);
87 status = 0;
88 break;
89 }
90 fclose(fh);
92 if (status == -2)
93 ERROR ("contextswitch plugin: Unable to find context switch value.");
95 return status;
96 }
98 void module_register (void)
99 {
100 plugin_register_read ("contextswitch", cs_read);
101 } /* void module_register */